Penguin Mail, a Free Rust-Based Email and Calendar Client for Linux, Reaches Version 1.0.0

Penguin Mail, an open-source email and calendar client for Linux, has reached version 1.0.0, according to a listing on Hacker News that links to the project's page. The software is free, licensed under GPL-3.0-or-later, and built for x86_64 Linux. The project is described in its listing as a Rust email client with an optional AI assistant. Some details come from the project's own description and have not been independently verified.

The app brings several kinds of accounts together in one place. Users can sign in to Gmail, Outlook.com, Hotmail, Live or Microsoft 365, as well as Fastmail, iCloud, Yahoo or any IMAP, POP3 and SMTP server. According to the project, Penguin Mail works out the server settings from the user's email address.

Users can read all accounts in a single inbox or view them one at a time. The app continues syncing from the system tray, showing an unread count and notifications that users can act on.

The calendar offers Day, Week, Month and Agenda views across every calendar on every connected account. Supported sources include Google, Microsoft and CalDAV, where the provider offers it. Users can respond to an invitation directly from the message in which it arrived. Contacts can be drawn from Google, Microsoft or CardDAV where available, and the app suggests recipients from people the user has written to as they type.

For security, Penguin Mail supports OpenPGP and S/MIME by signing and encrypting through the user's own GnuPG installation. The project says the app never holds users' keys or asks for a passphrase.

The client also lists mail rules in plain language and provides a form for adding new ones. It supports Gmail filters, Microsoft inbox rules and Sieve rules, where providers offer them.

An assistant feature is optional and stays off until the user chooses a model. According to the project, it can run on the user's own computer through LM Studio or Ollama, and it asks before sending mail or changing a setting.

On privacy, the project says Penguin Mail has no server of its own, no tracking and no ads. Gmail and Google Calendar accounts communicate directly with Google, and Microsoft accounts communicate with Microsoft Graph, so, the developers say, no other server sees the user's mail.

The information above is drawn from the project's own description as summarized in the Hacker News listing. Details such as release dates, the developers' identity and the full scope of the AI features should be confirmed against the primary source.